Democrats charged yesterday that the criminal indictment of Labor Secretary Raymond J. Donovan is the latest example of President Reagan's failure of leadership, but none of those surveyed said it would have an adverse effect on his reelection campaign.

Some Democrats, referring to the numerous scandals and allegations that have plagued the Reagan administration almost from the start, contended that Donovan's troubles reintroduced the "sleaze factor" into the campaign.

But House Speaker Thomas P. (Tip) O'Neill Jr. (D-Mass.) appeared to voice the opinion of many Democratic colleagues when he said that, although opinion polls show that many people do not like Reagan's policies, he is personally popular, and that "the sleaze factor never rubs off" on the man they call "the Teflon candidate."

Democratic presidential nominee Walter F. Mondale criticized Donovan yesterday as "the weakest secretary of labor in modern history" but said he should be presumed innocent and removed from office only if there is reason to believe that the charges are true. Mondale contended that the case is a test of Reagan's leadership.

On the ethics issue generally, Mondale said, "There has been a tacky element to this administration."

But he also said, "There will always be in any administration . . . , regrettably, examples of where public officers violate the public trust . . . . I think what really counts is how the president handles this matter.

"The president has a duty right now to investigate whether there is reasonable grounds to believe these serious charges are true. And if so, Donovan ought to be removed . . . . If Reagan doesn't do that, then I think that will strengthen the case that they're inattentive to the public trust . . . ."

Mondale has hit hard at what he considers Reagan's failure of leadership since the bombing of the U.S. Embassy annex in Beirut last month, but opinion polls indicate that the public's perception of Reagan as a strong leader is one of his major political assets.

Many Democrats have long been frustrated by what they perceive as Reagan's insulation from the real world and his refusal to take responsibility for his administration.

"There seems to be a universal reaction that Reagan is a decent fellow," said Greg Schneiders, a strategist in Ohio Sen. John Glenn's presidential campaign and a political consultant. "Mondale and the others aren't in much of a position to press Donovan's indictment now. They should have done it before he was indicted and went into court. It's like religion in the campaign -- it's peripheral. If it doesn't go to the issue of war and peace, forget it."

The voters tend to absolve popular presidents from scandals in their administrations, as they did with Dwight D. Eisenhower when his White House chief of staff, Sherman Adams, got into trouble. And some Democrats believe that the difficulty Rep. Geraldine A. Ferraro (D-N.Y.), their vice-presidential nominee, had with her husband's finances has at least partially offset the Donovan issue.

"As a former prosecutor, I will make no comment," Ferraro said yesterday. "I think it is a difficult thing for me to comment on, quite frankly, because I've been the subject of many, many accusations, unfairly."

There is also the feeling that if Reagan has not been touched by earlier scandals and allegations, he won't be by this.

Donovan has spent much of his 44 months in office dealing with charges that his New Jersey construction firm had ties with organized crime. A special prosecutor concluded in 1982 that there was insufficient evidence to bring criminal charges against him.

Edwin Meese III, a longtime friend and political colleague of Reagan who is his nominee for attorney general, was cleared last month by an independent investigator of charges of criminal misconduct in his financial dealings.

Paul Thayer resigned in January as deputy defense secretary after being accused of passing "insider" information on the stock market to friends; Thomas C. Reed resigned as White House national security adviser when accused last March of "insider trading;" Rita M. Lavelle, a former Environmental Protection Agency official, was sentenced to six months in jail and fined $10,000 for lying to Congress about her agency's activities.

Attorney General William French Smith came under fire in 1982 for benefiting from a tax shelter that the Internal Revenue Service had ruled was improper, and CIA Director William J. Casey has been criticized for being an active investor in the stock market while in office.